\documentclass{standalone}
\usepackage{tikz,ctex}
\usetikzlibrary{patterns}
\begin{document}
\footnotesize
  \begin{tikzpicture}[>=stealth,scale=0.7]
    \draw[thick](-2.25,-1)rectangle(2.25,1.0);
    \draw[thin](-2.2703,0.9543)--(-2.4531,0.5431);
    \draw[thin](2.2297,-1.0457)--(2.0469,-1.4569);
    \draw[thin](2.2703,0.9543)--(2.4531,0.5431);
    \draw[thin](-2.2297,-1.0457)--(-2.0469,-1.4569);
    \draw[thin,<->](-2.1079,-1.3198)--(2.3921,0.6802)node[pos=0.35,sloped,above]{$D_1$};
    \draw[thin,<->](-2.3921,0.6802)--(2.1079,-1.3198)node[pos=0.65,sloped,above]{$D_2$};
    \draw[thin](2.25,1.05)--++(0,0.3)(-2.25,1.05)--++(0,0.3);
    \draw[thin,<->](-2.25,1.2)--(2.25,1.2)node[midway,sloped,above]{$L$};
    \draw[thin](2.3,1.0)--++(0.5,0)(2.3,-1.0)--++(0.5,0);
    \draw[thin,<->](2.7,-1)--(2.7,1)node[midway,sloped,above]{$B$};
	\draw[line width=1.5pt](0,-1.8)arc(75:105:4.3)(0,-1.8)arc(255:285:4.3);
	\draw[thin](-1.1,-1.65)--(1.2,-1.65);
	\draw[thin,->](1.1,-2.1)--++(0,0.2);
	\draw[thin,<-](1.1,-1.65)--(1.1,-1.35)node[midway,sloped,above]{$f$};
  \end{tikzpicture}
\end{document}